I think regardless off the current situation that Geno is inevitable. There's always some reason the next never ever character can't get in but they always do.
Ridley: "Too big and Sakurai already vetoed him."
K Rool: "Sure, Ridley got in, but K Rool is irrelevant and forgotten."
B&K: Well yeah, K Rool got in, but Banjo is irrelevant, forgotten, AND third party."
Geno: "Banjo may have gotten in, but Geno is irrelevant, forgotten, third party, AND not a main character."
Each time "it's different because of X" and each time Sakurai adds the character anyway and cites fan demand as the reason. Despite the "smash bubble" argument, the "promotion" argument, and the "he's not popular in Japan" argument, the never ever characters are getting in one after the other and Geno is the last one left.
His time will come sooner or later.